This contract is designed to evaluate experimental HIV vaccine strategies in non-human primates before these vaccines would proceed into clinical trials. Vaccines will be tested for safety and immunogenicity. Challenge studies using Simian Immunodeficiency Virus (SlV) or chimeric HIV/SIV (SHIV) viruses will also be performed. Vaccine strategies investigated will include nucleic acid vaccines, recombinant proteins, whole-killed and attenuated viral vaccines as well as Immunologic adjuvants and delivery vehicles. The contract recipients must acquire, house, and monitor health and infection status on at least 50 non-human primates the first year and 25 additional animal in the subsequent years of the contract Biosafety facilities for housing and,laboratory work the animals must be provided. The contractors are also responsible for the development of protocols for each vaccine study and perform immunizations, and collection of blood, cells and tissue as required. lmmunologic and virologic assays will also be performed by the contractor. Specimens will be stored as required and specimens will be shipped as required by the program Project Officer. The contractors will supply written and electronically transmitted reports as specified. The SVEUs are a critical component in HIV vaccine research and development supported by the Division of AIDS.